Patent GB-671950-A (GB)
Title: Improvements in or relating to sliding doors
Inventor: BURROWS ARTHUR THOMAS CHARLES
IPC: E05F15/14
Filed: 1949-06-07
Abstract: 671,950. Sliding doors. KING, Ltd., G. W. June 6, 1950 [June 7, 1949], No. 15142/49. Class 20(iii) A horizontally sliding door 10 is given a limited downward vertical movement subsequent to its arrival in the closed position and a reverse movement prior to its removal from that position, and has at its leading and trailing edges a plurality of latch elements 20 which co-operate, when the door is in the closed position, with fixed brackets or the like 24 at either side of the door opening so that depending upon the direction of vertical movement of the door the latter is urged towards or away from sealing means around the opening, the latch elements being retractable behind the plane of the door during traverse movement of the door, and means being provided to project the elements into and from their operative positions on closing or opening respectively of the door. The door is suspended by a rope 11 from trolleys 12 which travel on track 13, one at least of the trolleys being driven to provide the traversing movement.. A hoist unit 15 which moves.the door vertically is mounted on a third trolley 14 on the track 13 includes an electric driving motor, gearing, and a winding drum round which passes a hoist cable 17 supporting a block 18 holding a pulley 18'. The rope 11 passes from one trolley 12, round pulleys 19 on the door, the pulley 18<SP>1</SP>, and further pulleys 19 to the second trolley 12. The spaced latch elements 20 are .interconnected by a bar 21 which is pivotally connected to links 22 movable about fixed pivots 23. The retraction and projection of the elements 20 takes place during the final part of the upward movement and the initial part of the downward movement of the door and is brought about by relative movement between the door and a dog 25 on cable 11. On upward movement of the door the dog 25 moves a pivoted lever 26 clockwise so that the cable 27 passing round pulleys 29 &c. swings the master link 30 upwardly to lift the bar 21 and retract the elements 20. but on the downward movement the dog 25 moves out of contact with the pivoted lever and the reverse movement takes place to project the elements 20, this projection being limited by stops. Alternatively, as in Fig. 7, movement of lever 31 by. dog 25 is transmitted by spindle 32 directly or through levers 33, 34 to the master link 30. Rollers 35, at the lateral edges of the door, run in guides 36 and are retracted and projected for the inward and outward movements of the door. Each roller is mounted on a bar 37 slidable in a slotted tube 38 rigidly mounted on the door edge, and a freely rotatable ball 41 is mounted at the lower end of a bar 40 slidable in a second similar parallel tube 39. Bars 37, 40 are linked by a slotted link 42 which co-operates with pins 43, 44 on the bars and has an extension 45 at a convenient angle and pivotally connected at the outer end to the lower end of bar 21. At the initial lowering of the door to project the elements 20, the link 42 is given an angular movement and raises bar 37 to lift roller 35 clear of the channel 36, and, on further lowering, bar 40 bears on the floor to keep constant the distance between the floor and the joint of arm 45 and bar 21. As shown in dotted lines in Fig. 8, the slots in link 42 then lie horizontally to permit inward movement of the door. The reverse movement takes place when the door is opened. An alternative hoist unit comprises an electric motor coupled through a fluid coupling and gearing.to a threaded rod journalled in the door structure. A nut is mounted on the rod and moves vertically relatively to the rod when the latter is rotated. A pair of ropes is attached to the nut and each passes round a pulley and is anchored to one of the suspension trolleys. With doors of considerable weight a direct lift hoist mechanism may be fitted to a control trolley on the overhead track, and include a hoist block suspended by a rope associated with a winding drum and passed round suitably disposed pulleys, so that the block is raised and lowered by the drum. A suspension rope passes from one trolley over pulleys on the door, a pulley on the block and other pulleys on the door to the second trolley. The timing of the operation of the hoist is suitably controlled. Specification 649,880 is referred to.